Alto, CA
How exposed is Alto to wildfire?
USFS's Wildfire Risk to Communities model puts Alto at the 50th national percentile for risk to structures, modestly above the national average for wildfire risk — a score built from 325 actual buildings. (Source: USFS's Wildfire Risk to Communities methodology.)
Fire likelihood alone (USFS's burn-probability figure) ranks Alto at the 51st national percentile — 1 points above its risk-to-structures score, a gap driven by how much is actually built there.
Alto's building exposure, zone by zone
99.4% of Alto's 325 buildings fall in USFS's Indirect exposure zone — ember cast rather than direct flame — against 0.6% Direct and 0% Minimal. Vent screens and roofing material matter more here than lot clearing alone.
How Alto compares
Alto ranks lower within California (10th percentile statewide) than its 50th national percentile suggests alone — a calmer spot in a state where wildfire risk generally runs high. Among the 31,521 US communities USFS scores, Alto ranks 15,904 for wildfire risk (1 is highest) and 20,949 by building count (1 is largest). Within California alone, it ranks 1,409 of 1,570 places by risk. See the full county-by-county picture for California on its state page.
Alto and the insurance market
Alto sits in California, one of two states that legally require a wildfire-risk disclosure at sale. California's FAIR Plan, the state's insurer of last resort, ended 2025 with 668,609 residential policies after adding 21,859 in Q4 alone — the kind of market shift a 50th-percentile score like Alto's can end up mattering for. More on the disclosure law.
Hardening a home in Alto
Because 99.4% of Alto's buildings sit in the Indirect zone, sealing the ember pathway (vents, roofing, gutters) is the intervention this page's data actually supports — see the home-hardening guide.
More on how this number was built
The methodology guide shows exactly how USFS turned 325 counted buildings into the percentiles shown above for Alto. For more on what indirect exposure implies beyond Alto, see the exposure-zones guide.